1. Field of the Invention
The present invention relates to a device for determining various types of trace nitrogen, and particularly to a device for separating and quantitatively measuring the contents of ammonium type nitrogen, nitrous type nitrogen, nitric type nitrogen and organic type nitrogen respectively.
2. Description of the Prior Art
Recently there have been serious problems arising out the nitrogen content and composition in environmental water such as river water, lake or pond water, and sea water, or waste water such as industrial waste water, process waste water, and hygenic waste water, which are said to cause a nutrient enrichment phenomenon for waters. Types of nitrogen contained in these water may be classified into four categories of an ammonium type, a nitrous type, a nitric type and an organic type. It is important to know the contents of the respective types of nitrogen to cope with the pollution problems of waste water.
There has hitherto been proposed a device for determining various types of trace nitrogen, in which two reaction tubes are provided and helium is used as carrier gas. In the first reaction tube, ammonium type nitrogen in the sample water is oxydized to nitrogen gas by a hypobromic ion containing reaction liquid, and after completely removing the accompanying moisture, quantitatively analyzed by gas chromatography. In the second reaction tube, nitrous type nitrogen in the sample water was reduced to nitrogen gas by an amidosulfonic acid reaction liquid, and after completely removing the accompanying moisture, quantitatively analized by gas chromatography. Nitric type nitrogen is reduced to nitrous ion by zinc powder and then analyzed by the above-mentioned second method. However, with this device, it is necessary to remove the nitrogen gas dissolved in each reaction liquid and sample water completely in advance, and it is further necessary that after the reduction to nitrogen gas, the accompanying moisture must completely be removed. Thus, such a device has drawbacks that the preliminary treatment is time-consuming, and the operation is cumbersome.